Internal combustion engine



N0V 9, 1943 LE ROY H. FRAILING 333,993

INTERNAL COMBUSTION ENGINE FiledJuly 25, 1941 m .54 19- 1- fb ff; ff 4342 D 0 Patented Nm, 99

1 ller neck and cap, partly broken away and in t filais.

This invention relates to liquid cooling sys..

tems for engines and more particularly to pressure controlling devicesfor such systems.

Liquid cooling systems for engines usually include a radiator having aiiller neck with an open end closed by a detachable cap, The neck isusually provided with a vent that communicates with atmosphere toprovidean overow outlet for the cooling medium in the otherwise closed system.

In order to reduce the heat exchange surface of the radiator, automaticvalve devices have been associated with cooling systems to shut od thevent to atmosphere so that the temperature at which the cooling mediumwill boil is thereby raised. These valve devices have included a blmetalthermostat and a spring that operates to seal the system while thetemperature therein is in some predetermined range, for example between195 and 225. The thermostat acts to open the valve below 195 and toclose it above such temperature, While the spring acts to retain thevalve in thermostat closed position until overcome by the pressuredeveloped in the system at 225"` Such devices have been generallyunsatisfactory because the loi-metallic thermostat acts too slowly inmoving the valve to open and closed positions and because ol unreliablecharacteristics caused by design.

An object of this invention is to provide a fluid heat exchange systemfor engines with an emcient pressure control means, of the type referredto, that canbe manufactured and in.- stalled at a relatively low cost.

Another object of the invention is to provide a unit thermostatstructure that can be detachably carried by a radiator ller cap forcontrolling pressure in an engine heat exchange system so that arelatively small, lightweight and rugged radiator structure can beutilized.

Still another object of the inventionis to provide a thermostat valveunit carried by the radiator cap of an engine cooling system consistingof a thermostat bellows and valves that will act to maintain thepressure in the cooling system within predetermined limits.

A further object of the invention resides in the provision of a valvestructure, of the character referred to, that is comprised of a minimumnumber of Aparts that can be manufactured and assembled at low cost.

Other objects of the invention will appear from the followingdescription takenv in connection with the drawing, which formsl a partof this specification, and in which:

Fig. l is a side elevational view of the engine and a cooling systemincorporating the invention;

Fig. 2 is a side elevational 'View the radiator section to show thesecuring means;

Fig. 3 is a fragmentary sectional view through the filler neck portionof the, radiator, its cap and the pressure control device, such devicebeing shown in the position occupied below a predetermined temperaturein the cooling system;

Fig. 4 is a view similar to that shown in Fig. 3, the valve device beingshown in closed position with the pressure in the cooling system belowatmospheric pressure;

Fig. 5 is a View similar to Figs. 3 and 4 but showing the valve devicein the open position occupied when there is maximum pressure in thecooling system.

Referring now to the drawing by characters of reference, Il) indicates aconventional type of engine that is provided with internal chambersthrough which a cooling medium, such as water, circulates in heatexchange relation. The cooling system includes a radiator Il having atop tank l2 anda lower tank I3. The top tank is connected with theoutlet end of the cooling chamber in the engine by connection it `and a.connection l5 leads from the lower tank of the scription is fnotbelieved to be necessary for a vclear understanding of this invention.

It has been customary to provide the upper tank of engine heat exchangeradiators with vent means, in the form of a filler neck it, to the openend of which a closure cap structure lll is detachably secured. It hasalso been customary to establish communication between the coolingsystem and air by the provision of an overflow conduit leading from thefiller neck, as indicated at 22. In the present invention the fillerneck deviates somewhat in design from the conventional in order tocooperate with a pressure control device as will appear hereinafter.

The cap structure il includes a cap l and a flexible metal disk 23. Thedisk will engage against and seal the outer end of the filler neck whenthe cap structure is attached. The outer `end of the neck is formed witha downwardly elongate or contract the bellows in response to temperatureconditions in the cooling system. A filler nipple 29 is xed to the topwall of the bellows and has a passage 33 extending axially therethroughby means of which the temperature responsive medium 28 can be introducedinto the bellows. The outer end of this passage 30 is suitably sealed bya layer of solder 3 I.

The bellows is slidably attached to the cap structure by means o! guidestem 32 extending through hollow rivet 33 applied to cap 9, this rivetalso being utilized in this instance to secure the flexible disk 23 tothe cap. The outer end of the stem, projecting through the hollow rivet,is enlarged to provide a head 34 and the inner end of the stem isthreaded so that it can be screwed upon a threaded portion 35 of nipple23. The guide stem 32 can slide axially in the rivet 33 and movement ofthe bellows away from the inner face of the cap structure is limited bythe head 34 engaging against the cap 9. A coil spring 36 is arrangedbetween the upper end wall of the bellows and the cap straucture andnormally holds the bellows projected from the cap structure to themaximum extent permitted by the stem head.

The radiator ller neck shown herein has an inner end 31 of reduceddiameter for the purpose of providing a shouldered valve seat 38 belowthe junction of the overflow outlet 22 with the neck. A- valve forengaging this seat, to seal the cooling system from atmosphere throughthe overflow outlet, is in the form of a disk 39 and it can be formed ofrelatively hard rubber or any suitable composition that can be utilizedwith a heat exchange medium employed for engines. This valve is arrangedto move with the lower end of the bellows and is shown attached to acarrier 40 that can be fixed to the bellows or to a stop member 4|attached to the lower end of the bellows, but in any event it isdesirable that this valve should travel with the lower end of thebellows. In the present instance the carrier is formed of sheet metaland comprises a base wall 4I', against which the valve disk 39 issuitably iixed, joined to a spaced upper wall 42.

Spring 36 urges the bellows into its extreme lower position as permittedby the head on the guide stem 32 and in such position when thetemperature in the cooling system is below some predetermined point, forexample 190, the valve will be clear of seat 38. Fluid in a-full coolingsystem will expand to some extent before it reaches the temperaturementioned and is free to flow to the outlet 22 as the valve 39 will beopen, the position of the thermostat unit under such circumstances beingshown in Fig. 3. When the temperature in the cooling systemreaches 190,or whatever pre-A determined degree is decided upon below the nor,- malboiling point of the cooling uid, the bellows will expand axially andwill carry the valve 33 therewith to engage the seat 38, as shown inFig. 4, and thereby seal oif the fiuid cooling system from the outlet 22that is open to atmosphere. With the bellows expanded the valve can beunseated only by pressure in the cooling system and the extent of suchpressure required to unseat the valve is determined by the pressureexerted by spring 33. This spring pressure can be such as to hold thevalve seated until some desired pressure in the cooling system isreached, as caused by temperature above the normal boiling point of thefluid in the cooling system, the valve being shown in such unseatedrelation in Fig. 5. The arrangement can be such that the valve will notbe open until the temperature in the system reaches approximately 225which can be the boiling point for the cooling uid when the system issealed.

The structure so far described takes care of increased pressureconditions in the cooling system but it does not provide for pressureconditions in the cooling system less than atmospheric resulting fromcooling of the heat transfer medium while the valve 39 is closed. Inorder to take care of such a vacuum condition, a valved by-pass means isprovided. The carrier 40 is made considerably larger in diameter thanthe bellows and is provided with a plurality of ports 43 in its upperwall 42 and with an axially extendinggange 44 forming a passage. Thepassage through the lower wall 3l of the valve carrier and the parts 33form passageways that are in communication with atmosphere through theoverflow outlet 22. The passage in the lower wall of the carrier isnormally closed by one-way valve means associated with the passage inthe flange d4. Flange M projects through a central opening in the valvemember 39 and the end thereof can be spun over to retain the valvemember. Valve 45 is arranged beneath the ange to engage against thevalve member 39 to shut oi communication between the cooling system andatmosphere through the by-pass. A stem 36 is screwed into the valve 45and extends through the passage formed by the ange M, this stem having ahead 4T located between the upper a'nd lower walls of the carrier. Coilspring 48 is arranged between head l1 and base wall M' of the valvecarrier to normally hold the valve 35 seated against the valve member3S. This spring 38 is selected to exert pressure which will be overcomeby a desired pressure drop in the cooling system below atmosphericpressure. For example, the spring can be arranged to permit the valve 35to be opened when the pressure in the cooling system becomes one poundless than atmospheric pressure. When the valve 45 is thus openedpressure in the cooling system will rise and thus cannot drop below theone pound less than atmospheric pressure. The radiator and connectionswill thus be prevented from collapsing under the force of pressurereduction in the cooling system. As the valve 33 will be open below andwill open above 225, due to the developed pressure overcoming the actionof spring 36, and as the system will be opened to atmosphere when thereis a one pound pressure drop below atmospheric pressure when the valve3S is closed, the possible pressure range in the cooling system islimited.

Through the use of the thermotat unit, the cooling system will be opento atmosphere during initial expansion of the cooling uid and will besealed below some predetermined high temperature to raise the normalboiling point of the cooling iiuid. As a result, the radiator structurecan be reduced in cooling area and of relatively light weight as theinternal pressures are controlled to hold breathing within small limits.The stop member 4| is employed to limit the axial extension of theflexible metal bellows 2l so that it can not be distorted sufllcientlyto take a permanent set.

Although the invention has been described in connection with a specificembodiment, the principles involved are susceptible of numerous otherapplications which will readily occur to persons skilled in the art. Theinvention is therefore to be limited only as indicated by the scope ofthe appended claims.

What is claimed is:

l. In a iluid circulating engine cooling system having a radiator, aradiator .fjller neck having an cutletintermediate its ends open toatmosphere and a shouldered base portion forming a valve seat, a sealingcap structure detachably applied to the outer end of said neck, athermo'- stat bellows adjacent the base o1' said cap structure, acarrier ilxed to move with the base end of said bellows, a disk valveilxed to the carrier and adapted to engage the neck seat to seal thesystem from atmosphere, a stem xed to the upper end of said bellows andconnected with the cap structure for limited axial movement relativethereto, a spring between the capstructure and the bellows projectingsaid bellows to maximum position away from said cap structure, saidvalve being clear of said seat when the bellows is contracted and inextreme position away from said cap structure, said valve engaging saidseat upon axial expansion oi said bellows in response to a temperaturebelow that at which pressure in the system will overcome said spring tounseat the valve, said valve and carrier having passage meanstherethrough open to atmosphere, and a valve member movable with andengaging said disk valve to shut oil' the passage means, said valvemember moving out of closed position in response to a predeterminedpressure drop in the cooling system below atmospheric pressure.

2. In a liquid cooling system .for an engine, the combination with ventmeans for the system. oi means for closing the vent means during apredetermined high temperature range in the system including a valvemember having a port therein through which the system communicates withatmosphere, and valve means closing said port but opening said port inresponse to a predetermined pressure drop in the system belowatmospheric pressure.

3. In a liquid cooling system for an engine, the combination with ventmeans for the system, of a valve member adapted to seat in the ventmeans, means for seating said valve member in the vent means during apredetermined range of high temperature in the system, and means forby-passing the valve member while seated only in response to apredetermined pres- 'sure drop in the system below atmospheric pressure.

4. in a liquid cooling system for an engine, the combination with ventmeans for the system, of a valve member adapted to seat in the ventmeans, a bellows thermostat operatively connected to seat said valvemember when extended, a spring engaging the bellows thermostat opposingopening thereof when seated, and means by-passing the valve, whenseated, in response to a predetermined pressure drop in the system belowatmospheric pressure.

5.In a iluid cooling system for an engine having a radiator filler neckwith a top, a shouldered base portion forming an interior valve seat andan outlet to atmosphere .between the top and the seat, and a sealing capstructure detachably applied to the top of the iller neck, control meanscomprising a thermostat bellows adjacent the base of said cap structure,a disk valve movable with the bottom of said bellows for engaging theseat in said filler neck, means connecting the top of said bellows withsaid cap structure for a limited axial movement relative thereto, and aspring acting between the top of said bellows and said cap structurenormally urging the bellows away from the cap structure, said valveclearing the seat below a predetermined temperature in the coolingsystem and engaging the seat above such temperature due to contractionand expansion o! the bellows, said valve being unseated against theaction of the spring while the bellows is expanded when pressure in thecooling system developed by a predetermined temperature above the normalboiling point of the cooling'tiuid is present.

6. A control device for engine cooling systems having a vented radiatorilller neck and a seallng cap structure applied to the radiator iillerneck comprising a thermostat bellows depending from the underside ofsaid cap structure, a valve movable with said bellows, a stem fixed tosaid bellows and mounted to move axially through said cap structure, ahead on said stem on the upper side of said cap structure, and a springbetween the bellows and the underside of said cap structure urging saidbellows away from said cap structure to the extent allowed by said head,the engagement of said head with said cap structure limiting the inwardmovement of the bellows to hold the valve unseated when the temperaturein the cooling system is below some predetermined degree.

7. A pressure control device for engine cooling systems having a ventedradiator iilier neck with a valve seat therein and a cap applied to theneck comprising a thermostat bellows located beneath the cap, a valveconnected to one end of the bellows and engageable with the seat, aguide stem xed to the other end o1 the bellows and slidable through thecap. means on said stem above said cap and engageable therewith to limitthe movement of the guide stem suiilciently to prevent seating of thevalve when the temperature in the cooling system ls below apredetermined degree, and a spring between the bellows and the capurging the bellows away from the cap.

8. A control device for an engine cooling system having a neck with avent and a valve seat hetwecn the system and the vent, a cap applied tothe neck, a disk valve engageable with the seat in the neck, a carrierfor the valve, a thermostat bellows having one end fixed to the carrierand the other end adjacent the cap, a spring actingt to space the capand the adjacent end of the bellows. a guide rod slidably mountedthrough the cap and xed to the bellows, and means on the end. oi' therod outside of the cap limiting movement of the bellows and carrierabove a predetermined temperature in the system to an extent unseatingthe valve, the valve being seated above such predetermined temperatureby expansion ci' the bellows and being unseated above such predeterminedtemperature by predetermined pressure ln the system suillcient to biassaid. spring.

LE ROY H. FRAIIJNG.

DISCLAIMER 2,333,99'3r-LejR9y`H. Frailng, Detroit Mich. INTERNALCouBUs'rloN ENGINE.

Patqnmdqtd Novj. 9, 1943. bisclaimer filed June 24, 1946, by thea'ssmfackard Motor Car Company.

Hereby enters this disclaimer to claim 2 of said Letters Patent.

[Qcal Gazeta July 80, 1946.]

